Pneumatic tool.



JL F. CLEMENT.

PNEUMAHC TOOL APPLICATION FILED APR. m, 1915.

Patented Nov. 16, 1915.

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WITNESSES:

J. F. CLEMENT.

' PNEUMATIC TOOL.

APPLICATION FILED APR.10. I915. I lifiQfiYg, Patented Nov. 16, 1915.

2 S HEETS-SHEET 2.

WITNESSES 'INVENTOR JOHN CLEMENT, 0F PHILADELFBHIA, PENNSYLVANIA.

PNEUMATIC TOOL.

income.

Specification of Letters Patent.

Patented Nov. is, 1915.

Application filed April 10, 1915. Serial No. 29,516.

T 0 all whom it may concern:

' Be it known that 1, JOHN F. CLEMENT, a citizen oi the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented a certain new and useful Pneumatic Tool, of which the following is a specification.

My invention relates more particularly to pneumatic tools of the valveless type which are commonly known in the art as stone tools, since they are especially adapted for cutting or shaping stone, although, as is apparent, they are not limited to such use.

My invention consists of a novel construction of a piston, and novel means for admitting and exhausting the motive fluid with respect'to the piston and. the, chamber in which it is adapted to reciprocate, whereby additional live motive fluid acts against the piston during its forward travel, and whereby the piston cushioned in a novel manner during its rearward movement.

My inventionaturther consists of a novel construction of a piston and a novel construction of a casing having ports and passages arranged in a novel manner therein.

It further consists of other novel features of construction, all as will be hereinafter more clearly set forth.

Figure 1 represents a sectional elevation.

of a valveless pneumatic tool, embodying my invention. Fig. 2 represents a sectional. View of a portion of the casing showing the exhaust ports and passages. Fig. 3 represents a sectional elevation similar to that seen. in Fig. 1, but showing the parts in a different relation with each other. Fig. 4 represents a sectional elevation of another embodiment of my invention. Fig. 5 represents a sectional view oi the casing seen in Fig. 1, showing the exhaust ports and passage. Fig. 6 represents a sectional elevation showing the parts seen in Fig. 4: in a dili'erent relation with each other. Fig. 7 represents a sectional view of an embodi ment of my invention illustrating the manner in which the casing and its adjuncts are preferably made in practice.

Similar numerals of reference indicate corresponding parts.

Referring to the drawings :-I have shown herein typical embodiments oi my invention, but it is .to be understood that the inventive idea herein involved is capable of various mechanical expressions within the scope of the appended claims.

Considering firstFigs. 1 to 3 inclusive, 1 designates the casing of a pneumatic tool embodying my invention and shown for purpose of illustration as comprising an outer casing 2, an inner easing member 3, and a removable plug or closure 4 in threaded engagement at 5 with the casing. 6 designates the inlet for the motive fluid which is threaded to receive the nipple connected with the hose leading from a source of motive fluid supply. v7 designates an inlet passage through the plug 1, which communieates with a passage 8 in the casing, so that the ports 9 and 10 are at all times in communication with live motive fluid. 11 design'ates the piston chamber or diiferential bore of the casing, having at one end a bore 12 of reduced diameter, into which is adapted to extend the reduced end 13 of a piston 14. 'The piston 14 is provided with a groove 15, thereby fori'ning the heads 16 and 17 which are of greater diameter than the rear end 13 of the piston, and are adapted to reciprocate in the enlarged bore 01 the piston chamber 11. 1S designates the forward portion of the piston, which is of reduced diameter and forms an impact member having its forward end adapted. to con tact with the inner end of a working tool 19, which extends into a bushing 20. The

bushing 20 has its outer face preferably tapered and the bushing has a driving fit in the aperture 21 opening through the forward end of the casing. '22 designates an aperture through which the forward end of the piston is adapted to pass. The other ports and passages for the motive ii dtwill be described in connection with the opera tion. 7

in. the operation, assuming that the parts are in the position seen in Fig. 3, the piston has been moved rearwardly so the live motive fluid may pass from port 10 into piston chamber 11 and around groove 15 of; the piston, and thence through port 23, passage Bi and port 25.ii1to the piston chamber in rear of the piston, and the live motive fluid imparts to the piston its initial forward movement. As soon as the piston head 16 opens thev port 9, live motive fluid, entering through said port 9, enters the piston chant her in rear of the head 16, thereby accelerating the movement of the piston and, increasing the force of its impact against the working tool. The air in front of the piston exhausts through port 26 and exhaust passage 27 to the atmosphere. As the piston moves .forwardly, the head-17 thereof 'uncovers the port 28, so that live motive fluid passes from inlet passages 7 and 8 and port 10 into the piston chamber 11 and around groove 15 of the, piston, through port 28,

passage 29, and port 30, into the piston chamber 11 in front of the piston head 17. The rear end of the piston has at this time uncovered the port 31, so that exhaust in rear of the piston takes place through port 31 and passage 27. As soon as the head 16 covers the port 9, the air directly in rear of saidhead 16 is trapped, thereby forming an elastic cushion to absorb the shock of the return stroke of the piston. As the head 16 covers the port 9, the port 23 is uncovered. so that live motive fluid may enter in rear of the piston, and the cycle of operation just described is repeated.

In Figs. 4, 5 and 6, another form of my invention is shown in which, after the initial admission of motive fluid to advance the piston takes place, additional motive fluid is admitted to accelerate the advance of the piston, and in which the piston is cushioned on its rear stroke.- The casing 32 has an inner casing member 33 and a' removable threaded plug or closure 84, which closes the rear end of the piston chamber 35,, which is of less diameter than the forward end 37 designates the piston having the heads 38 and 39 of thesame diameter and connected by the neck 40, which forms a groove around the piston. 41 designates an enlarged head extending from the head'39 and terminating 1n a forward extension or striker 42 of reduced diameter adapted to pass through the aperture 43 and impact against a working tool 44. 45 designates a bushing secured in an aperture 46. The inlet 47 is threaded to receive a connection from the source of inotive fluid supply and communicates by a passage 48 with a port' 49, so that live m0- tive fluid can pass through port .49 into piston chamber around groove 40 of the piston and through port 50, passage 51 and port 52 into the piston chamber in rear of the piston. The parts are now in the position seen in Fig. 6, and the piston moves forwardly and the. head 41 uncovers port 53 and live motive fluid passes into the .piston chamber and acting against head 41, accelerates the movement of the piston. Exhaust in trontof the piston takes place through port 54 and passage 55 to the atmosphere. During the forward movement of the piston, as'soou as head 39 uncovers port 56, live motive fluid passesfrom port 49 around groove 40 of the piston, through port 56, passage 57, and port 58, into the piston chamber in front of the head 41 and the piston begins its rearward stroke. port 53, the" motive fluid is trapped and a cushion for the piston is formed. Exhaust As the head 41 passes in rear of the piston takes place through port 59 and passage 55. The inner casing has a working or driving fit in the outer casing.

In the embodiments seen in Figs. 1 to 6 inclusive, 1' have shown the casing or housing .for thepiston as being made in section,-

Since the above description of the preferred manner of constructing the casing so that the piston may be readily removed for inspection or repair by removal of an end closure or plug will be clear to one skilled in the art, I have deemed it unnecessary'to turther illustrate the same.

It is to be understood from the foregoing that my invention is susceptible of changes in various particulars within the scope of the appended claims without departing from the spirit and scope of the invention.

Having thus described my invention,-what I claim as new and desire to secure by Let ters Patent is 1. A pneumatic tool of the valveless type, comprising a casing having a differential piston chamber, a solid, unapertured piston within said chamber and having an enlarged head, means to introduce live mot'ive fluid in rear of said piston to initially advance the same, means to introduce live motive fluid in rear of said enlarged head on a predetermined advance? of said piston, and exhaust ports and passages communicating with said bore.

- 2. A pneumatic tool of the valvel'ess type,

piston to initially advance the same, means iii to introduce live motive fluid in rear of said enlarged head on a predetermined advance of said piston, and exhaustports and passages communicating with said bore, and

said means to introduce live motive fluid in rear of said enlargedhead being arranged to form a cushion of air on the rear stroke of said piston.

3. A pneumatic tool of the valvele'ss type,

comprising a casing having a differential to introduce live motive fluid in rear of said enlarged head on a predetermined advance of'said piston, and exhaust ports and passages communicating with said bore, and said means to introduce live motive fluid in rear of said enlarged head being arranged to form a cushion of live air on the rear stroke of said piston.

4:. A pneumatic tool comprising a casing having a differential piston chamber, a piston within said chamber having enlarged heads connected by a neck and having at its rear end a head of smaller diameter, means to admit live motive fluid in rear of the smaller head to effect the initial advance of said piston, and means to admit live air in rear of one of said enlarged heads on 'a.

predetermined movement of the piston to aid 1n the advance movement thereof, said last-named means being arranged to form an air cushion in rear of .one of said en-' larged heads on the rearward movement of said piston.

,5. A pneumatic tool comprising a-casing having a diflerential piston chamber there in, a-solid, unapertured piston in said chamher havinga reduced end portion, a plurality of spaced enlarged heads and an impact portion at its forward end, means to admit live motive fluid in rear of said end portion and in rear of-one of said enlarged heads to effect the initial advance of the piston, means to admit live motive fluid in rear of the other of said enlarged heads on a. forward movement of the piston, and exhaust ports and passages communicating with said chamber.

6. A pneumatic tool comprising a casing havinga differential piston chamber therein, a piston in said chamber having a reduced end portion. a plurality of spaced enlarged heads and an impact portion at its forward and means to admit live motive fluid in rea of said end portion and in rear of oneof said enlarged heads tocfl'ect the initial advance of the piston, means to admit live motive fluid in rear of the other of said enlarged heads on a forward movement of the piston and to trap a portion of such live air on a rearward movement of the piston, and exhaust ports and passages cominunicatinp; with said chamber- 7. A pneumatic tool comprising a casing, a piston to reciprocate therein, means to admit motive fluid to a portion of the piston to initially advance the piston, means i: admit livemotive fluid to another portion of the piston to effect its further advanremci'it on a predetermined forward movement and to form an air cushion on its said piston to initiallv advance it,

rearward movement, and means to exhaust motive fluid from said casing.

8. A pneuniagtic tool comprising a casing, a reciprocatorf piston therein comprising a plura ity of heads of uniform diameter connected by a neck and a head of a diilcrent diameter on one side of one of said heads, means to admit live motive fluid in rear of means to admit live motive fluid in rear of the head of different diameter, on a. predetermined forward movement oi the piston to further advance it, and means to eiiect the exhaust of exhaust motive fluid from the casing.

9. A pneumatic tool comprising a casing, a reciprocatory solid and unapertured piston therein comprising a plurality of heads of uniform diameter connected by a neck and a head of a greater diameter on one side of one of said heads, means to admit live nio tivefiuid' in rear of said piston to initially advance it, means to admit live mttive fluid in rear of the head of greater diameter, on

' a predetermined forward movement of the piston to further advance it, and means to eliect the exhaust of exhaust motive fluid from the casing.

10. A pneumatic tool comprising a casing having a differential piston chamber, a piston therein having at its rear end a plurality of heads of uniform diameter and connected by a neck and a, forward head of enlarged diameter, means to admit live motive fluid to the rear end of the piston to initially advance it, means to admit live -motive fluid in rear of the forward head to advance the piston and to cushion the piston on its rearward stroke. and means to effect exhaust of fluid from the piston chamber.

. 11. A pneumatic tool comprising a casing having a diflerential piston chamber, a piston therein having at its rear end a plurality of heads of'uniform diameter connected by a neck and a forward head of enlarged diameter and a striking portion of less diameter than'therest of the piston, means to admit live motive fluid to the rear end of the piston to initially advance it, means to admit live motive fluid in rear of the forward head to advance the piston and to cushion the piston on its rearward stroke, and means 

